直接看代码,解释。主要是用到图片处理的
PorterDuff.Mode.SRC_ATOPSRC_ATOP
源像素和目标像素相混合让上层图居中显示,达到加框效果
- import android.app.Activity;
- import android.graphics.Bitmap;
- import android.graphics.BitmapFactory;
- import android.graphics.Canvas;
- import android.graphics.Paint;
- import android.graphics.PorterDuff;
- import android.graphics.PorterDuffXfermode;
- import android.graphics.Rect;
- import android.os.Bundle;
- import android.widget.ImageView;
- public class MainActivity extends Activity {
- private ImageView imageView;
- @Override
- protected void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
- setContentView(R.layout.activity_main);
- imageView = (ImageView) findViewById(R.id.imageView1);
- // 获得imageview中设置的图片
- Bitmap lay1 = BitmapFactory.decodeResource(getResources(),
- R.drawable.icon_folder);
- Bitmap lay2 = BitmapFactory.decodeResource(getResources(),
- R.drawable.mobileqq);
- // 获得图片的宽,并创建结果bitmap
- int width = lay1.getWidth();
- Bitmap resultBmp = Bitmap.createBitmap(width, width,
- Bitmap.Config.ARGB_8888);
- Paint paint = new Paint();
- Canvas canvas = new Canvas(resultBmp);
- canvas.drawBitmap(lay1, 0, 0, paint);// 画下层
- // 让上层的图标居中显示
- int top = 0;
- if (lay1.getHeight() > lay2.getHeight()) {
- top = (lay1.getHeight() - lay2.getHeight()) / 2;
- }else{
- //这里可以判断图片是否大于框,进而再继续获取大于的多少,进行上层图片的缩放,然后再进行交集,方法就不写了
- }
- int left = 0;
- if (lay1.getWidth() > lay2.getWidth()) {
- left = (lay1.getWidth() - lay2.getWidth()) / 2;
- }else{
- //这里可以判断图片是否大于框,进而再继续获取大于的多少,进行上层图片的缩放,然后再进行交集,方法就不写了
- }
- paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_ATOP));// 选择交集去上层图片
- canvas.drawBitmap(lay2, left, top, paint);
- imageView.setImageBitmap(resultBmp);
- }
- }
来源: http://www.phpxs.com/code/1001758/